Mortise-cutting tool.



L. H. LAIRD.

MORTISE CUTTING TOOL.

APPLICATION HLED JUNE 1. 1918.

1,297,577, Patented Mar. 18,1919.

INVENTOR Zawra/zczHZa/rai ATTORNEY 'Tozall whom-iimay concern:

' Yreka,

LAWRENCE H. Lanai), or XREKA, ,o LIroa IA.

Mo RTIseoU'r'rI Ne moor..-

i Specification of Letters Patent.

PatentedMarAS, 1919.

Applicationfiled June 1, 1918. Serial No. 237,807.

Be it known that I, LAWRENCE H. LAiRD, a citizenof the UnitedStates, residing at in the county of Siskiyou and State of- California, have invented certaln new and useful Improvements in Mortise- CuttingfTools, of'which the following is aspecific'ation.

This invention relates to a mortise cutting tool andhas-for its object to provide a simtple, convenient and portable tool designed to be detachably mounted'upon the strip of wood in Which it is 'desired to cut a mortise and after'being properly placed tomanually-operatea power device for forcing a pair of parallel chisels into the wood to cut the opposite longitudinal side of the mortise to the proper depth in a rapid and accurate manner and thus doing away with the necessity .and trouble of first boring holes in the wood and afterward'trimming out theasame to proper size.

With these objects in view, together with. others which will appear as the description proceeds, the invention resides in the novel formation, combination and arrangement of parts, all as will be described more fully hereinafter, particularly pointed out in the claims, and illustrated in the drawings, in which,

Figure 1 is an elevation of the improved mortise cutting tool.

Fig. 2 is a vertical sectional view on the line 2-2 of Fig. 1, and

Fig. 3 is a diagrammatic view in plan showing the tool attached to a work bench in position for use.

In the drawings, on the lower end of 10 indicates two postseach of which is a finger 11 extending at a right angle to said post through which is formed a threaded opening to receive a pressure screw 12 carrying a manually operable head 13 on one end and a foot piece 14: on the opposite end to bear against the strip upon which the tool is mounted. Above each of the fingers 11 is a finger 15 parallel to the finger 11 and spaced therefrom and designed to bear against the opposite side of the material, the parts thus described forming a clamp for each post 10.

At the opposite end of each post is a stud 16 on which studs are pivoted the opposite ends of a connecting bar 17, these ends being provided each with a sleeve 18 for the passage therethrough of one of the studs 16. The bar is held in place on the screws 28 is a chisel 29. larly carried in the clamp 27. The Chisels studs by nuts 19 which, whilepreventing the disengagement of the bar and posts, permits easyrotation of the studs within the sleeves.

The center ofthe'bar l7 is madewith an enlargement 20 through which is formed a threaded openmg fora screw stem 21, on the outer end of which 'is fixed a hand wheel-22 or other means for rotating the stem 21.. The

'from corresponding sides of the arms 24:. Similar clamps 27 are slidably mounted on the portlons of the rods 25 projecting from the opposite side of the arms. Removably mounted in the clamps 26 by means of A chisel 30 is simi- 29 and 30 are furnished in sets of two of different widths "and lengths to accommodate the tool for cutting mortises of various. lengths and depths. As a depth guide to the user, each blade has an inch scale on the outer side at the opposite end thereof as shown at 31, which scales may, if desired, be marked on the end of the blade as shown opposite end ofthe screw stem is swiveled in a block'23 from-opposite sides" of from opposite sides of the in Fig. 2. The blades fit into notches in the ends of their clamps and are secured therein as shown by the screws or bolts 28 passing through the clamp and blades.

For adjusting the blades 29 and 30, which it is to be understood lie parallel to each other, the clamps 26 and 27 are slidable on the rods 25, but may be temporarily secured immovable on said rods by thumb screws 32 threaded in the clamps and adapted to bear upon the rods.

In using this tool it is possible to secure it to one end of a work bench A in angular position as in Fig. 3, one clamp being fastened to the end of the bench and the other to an adjacent side. After the width and position of the mortise has been properly marked on a strip of wood B, blades of proper size are mounted in the clamps 26 and 27 and the latter adjusted to set said blades to the width of the mortise by sliding them on the rods 25 and when properly positioned, theyare clamped to said rods by the thumb screws 32. The marked strip of wood is then placed under the tool, supported on the bench A, and the screw stem.

. necessary. The ends of the mortise are then cut in the usual manner by a hand chisel and the material between the cuts removed. The foregoing description and the drawings have reference to what may be considered the preferred, or approved form of my invention. It is to be understood that I may make such changesin construction and arrangement and combination of parts, materlals, dlmenslons, et cetera, as may prove expedient and fall within the scope of the appended claims.

Having thus fully described my invention, what I claim as new and desire to secure by Letters Patent, is:

1. A mortise cutting tool comprising a one end, a head swiveled to pair of upright posts having independent clamping devices at the lower end and studs rising from the upperend, a connecting bar pivotally mounted on said studs, a screw stem threaded through the connecting bar and having a hand wheel at its upper end screw stem threaded in said connecting bar 7 and having a manually operable means on t the opposite end of sald screw stem, two rods carried by said head in parallel relation, clamps adjustable on said rods, and a pair of chisels carried by said clamps in parallel arrangement and adjustable to and from each other.

In testimony whereof I aflix my signature in presence of two witnesses.

LAWRENCE H. LAIRD.

Witnesses: v

B. K. COLLIER, R. O. COLLIER.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner: of Patents,

- Washington, D. G. 

